Consumers worldwide experience color damage to their clothing from exposure to the sun during drying and during wear especially for those consumers living in tropical and subtropical climates. Despite extensive efforts by the textile industry to develop light stable dyes and after-treatments to improve light-fastness of dyes, the fading of clothing still remains a problem.
It has now been discovered that visible light is responsible for a significant amount of dye fading on clothing. For example, visible light has a higher contribution to light fading than UV-A, which has a higher contribution to light fading than UV-B.
Antioxidants provide a broad range of sun-fade fabric protection for the consumer because their effectiveness is not dependent upon the absorption of light. Because antioxidant agents are expensive, it is desirable to select and utilize the most efficient compounds in order to minimize the cost of the compositions.
As noted above, visible light is responsible for a significant amount of dye fading on clothing. Because the absorption spectrum of the sunscreen compounds of the present broadly absorbs UVA, these agents provide broader sun-fade protection with less problems than is associated with the conventional sunscreens.
The incorporation of sunscreens and antioxidants into fabric softeners and detergents for various benefits is known in the art. For example, U.S. Pat. No. 4,900,469, Clorox, teaches antioxidants in detergents for bleach stability. Antioxidants have been used in softeners and detergents to prevent fabric yellowing and to control malodor. (See, JP 72/116,783, Kao.) JP 63/162,798, Lion, teaches the use of sunscreens to stabilize the color of fabric conditioning compositions. U.S. Pat. No. 5,134,223, Langer et al., issued Jul. 28, 1992, Lever, teaches copolymers with a UV-absorbing monomer and a hydrophilic monomer to provide both anti-fading and soil release benefits. This reference teaches the combination of a polymer of UV-absorbing monomers to a soil release polymer consisting of a hydrophilic group (e.g. ethoxylate) and hydrophobic group (e.g. terephthalate blocks). U.S. Pat. No. 5,250,652, Langer et al., issued Oct. 5, 1993, Lever, teaches copolymers containing at least one UVA light-absorbing moiety and/or one UVB light-absorbing moiety, one low molecular weight (i.e., monomeric) hydrophilic moiety, and optionally one hydrophobic moiety for fabric care (detergents, fabric softeners, etc.) and skin care applications (cosmetics, shampoos, sunscreens, personal cleansing compositions, etc.). The use of low molecular weight hydrophilic moieties allows a loading of UVA and/or UVB moieties of up to about 95% and provides better dispersibility of the polymer in an aqueous media. The optional hydrophobic moiety provides control over the deposition of the copolymer on a desired surface.
All of the above patents and patent applications are incorporated herein by reference.